Conventional image sensors are typically of the type in which, as FIGS. 7(a) and 7(b) show, an image sensor chip 73 is fixedly mounted through the intermediary of a conductive adhesive 74 on an opaque substrate 71 formed with circuit conductor layers 72. An electrode 73A of the image sensor chip 73 is connected individually with the circuit conductor layers 72 by wire bonding using fine wire of a metal such as that of gold or aluminum. The assembly is sealingly covered with a transparent mold resin material 76. A plurality of photo sensors (not shown) are arranged on sides of individual electrodes 73A of the image sensor chip 73.
One drawback of such an image sensor is that the electrodes 73A have to be connected individually with the circuit conductor layers 72 using fine metal wire 75, which involves very complicated wiring work. Another drawback is that the arrangement of the image sensor makes it difficult to adapt the electrodes 73A to be arranged at a reduced pitch.